Grease-gun.



W. U'. WATSON.

GREASE GUN. APPLICATION FILED 111 11.22, 1912.

Patented 0013.29, 1912.

WILLIAM U. WATSON, or CHICAGO, ILLINOIS.

GREASE-GUN.

Specification of Letters Patent.

' Patented Oct. 29, 1912.

Application filedApril 22, 1912. Serial No. 692,429.

To all whom it may concern:

Be it known that 1-, WILLIAM a citizen of .the-.United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Grease-Guns, of which the following is a specification.

My invention relates to pumps, more par--. .ticularly. of the type known ,as grease with the use of automobiles and the accessories thereof that for lubricating'thegear box and other parts of the machine it is common to employ heavy grease. This grease is usually non-fluid or at most semifiuid and therefore cannot be ejected from the gun as water or. oil would be ejected from a syringe or oilcan. Great pressure is necessary, the amountybeing greater than can be readily exerted by a person pressing upon the handle of the gun.

Various expedients have been tried and one of the objects of my invention is to provide means whereby the necessary pressure may be obtained from compressed air or other gas.

Another object of my invention is to provide means" for "maintaining a close fit between the piston and the sides "of the cylinder both when the gun is being filled'and grease is being'ejected.

Another object of my invention-is to provide means whereby the'user may have the choice of introducing the compressed air directly into the cylinder, or into a duct formed in the hollow piston and handle.

I obtain my objects by the mechanism illustrated in the accompanying drawings in which 7 Figure 1 is a central longitudinal section of the complete device. Fig. 2 is a side elevation thereof. Fig. 3 is a cross-section taken on line 3-3, Fig. 1, and Fig. 1 is a top view of the'packing ring for the piston. a -Similar reference characters denote like parts in the different views.

The cylinder 1 is provided at'its lower end with a cap- 2, which. willbe removed when the gun is being filled. Said cap is provided with a nozzle ,3 whereby-the grease may be introduced directly to the point re quired. At the upper end, the cylinder is closed by a cap 4. preferably provided with packing 5 and nut 6. In thepreferred form, cap 1 is also provided with a nipple U. WATSON,-

lit will be understood by those familiar 'ber of ducts 12 lead fromthe base of the just above the piston.

also has an internal duct 21 which commu- 7, where by compressed'airpr other actuating fluid may be introduced into the cylinder. 'This is normally closed by a -cap -8 1 I and may be provided with a ball check valve 7 j p 7 Within thecylirider is fitted a piston consisting of a piston body 10, having: n nular channel in its periphery adapted to contain the packing ring 11' shown separately in F 1g. t. .,This ring consists preferably of leather'and in order that it may be expansible, is discontinuous at one or more points. In-the-body of the piston, a numperipheral channel to the top of the piston. Thisadmits the actuating fluid to the back I of the packing ring, thus forcing the ring outward and perfecting the contact between the ring and the inside of the cylinder. This prevents leakage past the piston in either direction. y

A pistonrod 15 is fastened to the piston in .any suitable manner. This rodis hol-' low, being provided with a longitudinal duct 16 which communicates through a port 17 with the inside of the cylinder at a point At the outer end, the rod is provided with a handle 20 and this nicates with duct 16 inside of the piston rod.

By'preference the, duct 21 extends horizontally. to the end of the handle where it com-v municates with a'nipple 22 which is screw threaded at its outer end to enable'it' to be coupled with anair pump, gas tank orother source of actuating fluid under pres sure.- Nipple 22 is provided with a spring closed valve 23, havinga stem 24 which projects slightly beyond the end of the nipple as shown at the upper right corner of Fig. 1. The parts are so arranged that when the nipple is disconnected from the air hose, the thumb of the operator will naturally occupy a position adjacent to (jog valve stem 24, thus enabling him to control T valve*23 while his hand is in position upon Handle 20.

In operation let itbe assumed th at the del vice is empty and that the operator wishesto 1 5 fill it with the heavy grease herein above mentioned. He first removes the cap 2 and forces the piston down to the lower-end of the cylinder, Then, keeping his thumb off valve stem 24,- puts the open end of the cyl-' inder down into the grease and pulls upward on the handle. The upward movement of pit place of final use.

It will be noted that as the operator is thus filling the cylinder with the valve 23 closed, there will be no outlet for the air confined in the cylinder on top of the'piston. The result is that the air becomes compressed here and, entering the ducts 12 acts upon the back of the packing ring 11 and forces the latter out-ward. As the piston rises, the pressure behind the piston tends to increase, but the operator by pressing his thumb upon the valve stem 24 relieves the pressure and maintains it at the intensity which he thinks sufficient fortmaintaining the contact between the inside of the cylinder. 7

When the piston has risen tothe top of packing ring and the the cylinder, and the latter isfilled with grease, the operator replaces the cap 2 and nozzle 3 whereupon the device is charged and ready for use. If only a small amount of grease is to be ejected, the operator may attach the compressed air hose to the nipple 22 and the compressed air on entering will automatically open valve 23 and pass through the handle and piston rod and port 17 into the cylinder behind the piston. This will force the piston downward and eject the amountof grease required. The air hose may then be detached and the gunwill maintain the grease which ithas left. If it is desired to fill a gear box, which ordinarily has a capacity several times that of the grease'gun, the operator, instead of fastening the air hose to thenipple 22, may remove cap 8, and attach the air hose to the nipple 7. 'He can then fill and empty the gun any number of times without detaching the hose. This feature of the device,

*however, is not essential for when the device is in the hands of private users, it will not be called upon frequently for filling vthe gear box, andno time would otherwise be saved, by using the nipple 7 insteadof the nipple 22." 1

Attention 1s called to the fact that the packing ring is forced out-ward as well upon the downward movement of the piston as upon the upward movement thereof for in both cases is there compressed air on top -of the piston and this has access to the back of the packing ring. Thus the device is double acting with respect to the packing ring so that leakage is avoided no matter which direction the piston is moved;

Another characteristic of my device may be noted, to-wit; if the compressed air hose is connected to the nipple 7, and air is en- I tering through it, the speed of the downward moving piston may be regulated by manipulating the valve 23. Te illustrate, if the piston is traveling too fast, the movement may be retarded by opening the valve 23 and thus reducing the pressure above the piston without touching the air hose or its connection.

Having thus described my inventiomwhat I claim as new and desire to secure by Letters Patent, is: I

1. In a device of the class described, in combination, a cylinder having an opening at the lower end, a piston in the cylinder, a

piston rod having a duct therein communicating atone end with the inside of the cylinder above the piston and at the other end with the atmosphere, and a valve for controlling the outer end of said duct.

2. In a device of the class described, in combination, a cylinder having an opening at the lower end, a piston having a periph eral groove the bottom of which is in communication with the space'above the piston, anexpansible packing ring in said groove, a hollow piston rod having a port communicating with the inside of the cylinder at a point above the piston, said rod projecting througlrthe end of the cylinder, the cylinder being otherwise closed above the piston, and a valve for controllably releasing the air from said piston rod.

3. In a grease gun, incombination, a cylinder, a piston therein, a hollow piston rod projecting through the end of the cylinder and having a port communicating with the inside of the cylinder at a point above the piston, and means for controllably introducing compressed air and other gases into the cylinder through the piston rod...

4. In a grease gun, in combination, a cylinder. closed at the top, a piston therein, a hollow piston rod projecting through the end of the cylinder and havinga port com-, municating with the inside of the cylinder at a point above the piston,,a handle for operating the piston rod, and a valve in convenient position for,manipulat-ion by the hand of the operator when his hand is in position upon the handle, ,said valve being adapted to control the escape of air from the inside of the piston rod.

' 5. In a grease gun, in combination, a cylinder closed at the top, a piston therein, a hollow piston rod projecting through the upper endof the cylinder and having a port communicating with the inside of the cylinder at a point above the piston, a handle for operating the piston, said handle containing 3 a duct whichv communicates with the inside of the rod, and a valve in the handle for permitting and preventing, controllably, the escape of air from the upper end of the cylinder.

6. In a grease gun, in combination, a cy1-- with the space above the piston, an expansible packing ring in said groove, a port for admitting compressed.air into the top of the cylinder, and a valved duct leading through the piston rod from a point above the piston, inside of the cylinder for controllably relieving the air pressure above the piston.

7. In combination, a cylinder closedat the top, a removable cap at the bottom of the cylinder provided with a delivery duct, a piston having a groove in its periphery, ducts in the piston leading from the bottom of the groove to the top of the piston, a hollow piston rod having a port communicating with the inside of the cylinder at a point above the piston, a handle having a duct communicating with the inside of the piston rod, and a valve in the handle duct for normally preventing the escape of air therefrom, said valve being spring closed and being adapted to be opened by the finger of the user. I

In witness whereof, I have hereunto subscribed my name in the presence of two witnesses.

WILLIAM U. WATSON.

Witnesses: i

- HOWARD M. Cox,

Geo. J. UNDERLAND. 

